Grease gun



P. GRESSER June 24, 1930.

GREASE GUN Filed Dec. 8, 1928 MSR M1 EN wN mvwmw gwuanto'c SHOT/ms w s m 5 .w n

n @Q Q Patented June 24, 1930 1,766,897

. UNITED STATES PATENT OFFICE PETER GRESSER, OF DETROIT, MICHIGAN GREASE GUN Application led December 8, 1928. Serial No. 324,671.

The present invention pertains to a novel with an abutment having a longitudinal grease gun'of the type designed for the luport 6. The abutment rests against a flange brication of lbearings of motor vehicles and 7 atthe outer end of the tube 4. other machines. lVithinthe cylinder l is a piston 8 nor- 5 The principal object of the invention is mally held against the inner end of' the tube 55 to provide a device of this character whereby 4 by means of a spring 9 which also bears the lubricant is first trapped in a confined against a cap 10 covering the remaining` end volume and then, by a continuous stroke of of the cylinder. A plunger 11- is slidably the plunger ofthe gun, forced into the bearmounted in the axis of the cylinder, but is 10 inv. e supported centrally of the piston and in a 60 Vith this object in view, the gun comprises central boss 12 formed up from the cap 10.

a cylinder and a tube adapted to receive the Forwardly of the piston, the plunger has a lubricant. A suitable coupling is provided shoulder 13 which limits retraction of the for connecting the tube to the bearing. A plunger, and is then reduced in the nature 15 valved abutment is mounted in the outlet of a stem 14 and extends a considerable dis- 65 end of the tube, and adjacent this abutment is tance forwardly into the tube 4.

a sliding valve normally separated from the Between the abutment 5 and the plunger, abutment by a spring. A plunger slides the tube 4 contains a slidabley sleeve 15, the through the cylinder and tube and is normalforward end ofwhich is formed with a seatl ly spaced from the sleeve by a spring which 16 adapted to receive the reduced rear end 70 is stronger than that rst mentioned. When 17 of the abutment 5 as will presently appear.y the plunger is first actuated in the operation A comparatively light spring 18 is disposed of the device, the sleeve is permitted to apbetween the abutment and the sleeve, and a proach the abutment by the compression of stronger spring 19 is positioned between the the first mentioned weaker spring and bythe sleeve and the swaged rear end 4 of the 75 resistance presented by the stronger spring. tube 4. 'l This movement of the plunger and sleeve On the threaded end 3 is screwed a coupmerely confines the available lubricant to a ling member or nozzle 20 which contains a comparatively small volume, andv the next spider 21 against the flange 7. Into this movement of the plunger causes compression Spider is anchored one end of a rod 22 carry- 80 of the stronger spring and forces the confined ing a valve head 23. Slidable in the nozzle lubricant into the bearing. is a valve member or thimble 24 having a The invention is fully disclosed by way valve seat 25 adapted to cooperate with the of example in the following description and valve head 23 and equipped with an outer in the accompanying drawing, in xwhichpacking ring or gasket-26. The forward end 85 Figure l is a longitudinal section of the of the coupling body has a pair of internal device in idle condition and unattached to a lugs 27 for a purpose which. will presently bearing; and appear, and behind these lugs is a sliding cou- Fig. 2 is a similar detail section showing pling body 28 receiving the forward end of the device coupled to a bearing and at the end the stem 2 and abutting thethimble 24. A 90 of the first stage of its operation. Y spring 29 surrounding the stem 22 between Reference to these views will now be made the spider 21 and the thimble 24 tends to by use of like characters which are employed move the latter outwardly. to designate corresponding parts through- A check valve head 30 oats in the port 6 out. of the member 5 and is positioned to close the 95 The body of the device comprises a cylport when drawn inwardly. Finally, the inder l which tapers at 2 towards its outlet tube 4 has apertures 31 establishing commuend and is there externally threaded at 3. nication with the cylinder.

A tupe 4 within the tapered end 2 extends In the operation of the device, the lubrirearwardly from the tip and is there equipped cant contained in the cylinder is advanced to- 100 wards the tapered portion 2 by means of the spring pressed piston 8. In the idle position of the device, there is considerable space between the ported abutment 5 and the sleeve 15, which is filled with lubricant by the means described. Also, the thimble 26 is expelled outwardly to its limit by the spring 29 and closes against the valve head 23.

The nozzle is adapted for application to a fitting 32 of well known type having'facets 33 and grooves 34 by means of which the lugs 27 are locked thereto. In passing the nozzle 2O over the fitting for this coupling, the coupling washer 28 and thimble 24 are-.moved inwardly, whereby the valve seat in the latter is separated from and uncovered by the valve head 23. At the same time, the forward end of the stem 22 opens a check valve (not shown) in the fitting 32.

In the initial movement of the plunger 11, the weaker spring 18 is compressed against the resistance of the stronger spring 19, as shown in Figure 2, whereby the sleeve 15 is moved forwardly into engagement with the abutment 5. rl`he pressure with which the sleeve 15 is advanced, which is equal to the pressure of the spring 19 in its normal condition, is sutlicient to force lubricant into the passage leading to the bearine, but insufficient to overcome the resistance which the bearing presents to the injection of lubricant therein. In this manner a quantity of lubricant is trapped into a confined s ace between the bearing proper and the re uced plunger end 14 which is now received in the sleeve. 0n continued movement of the plunger, suiiicient pressure is required to overcome the spring 19, whereupon the. trapped lubricant is injected into the bearing. It will be noted that no resistance is set up by the valve 30 which is removed from its seat on the first stage of operation as shown in Figure 2.

When pressure on the plunger is released and the latter is retracted by the spring 19,

the sleeve 15 is also retracted by the spring 18. During this movement of the sleeve, a suction is created between the sleeve and the abutment 5, whereupon the floating valve 30 is drawn to a closed position against the abutment, and lubricant is drawn into this space through the ports 31 and the sleeve 15. v

Although a specific embodiment of the invention has been illustrated and described, it will be understood that various alterations in the details of construction may be made without departing from the scope of the invention as indicated by the appended claims.

What I claim is 1. A grease gun com rising a cylinder, an

outlet tube in one end t ereof, a ported abutment in said tube, a sleeve slidable in said tube, aj spring between said abutment and sleeve, a plunger slidably mounted in said tube and dimensioned for a sliding fit in said sleeve whereby to drive lubricant through said sleeve, a stronger spring between said sleeve and plunger, and means for admitting lubricant from said cylinder to said tube.

2. A grease gun comprisin a cylinder, an outlet tube in one end thereo a ported abutment in said tube, a check valve in the port of said abutment and mounted to open outwardly of said cylinder, a sleeve slidable in said tube, a spring between said abutment and sleeve, a plunger slidably mounted in said tube and dimensioned for a sliding t in said sleeve whereby to drive lubricant through said sleeve, a stronger spring between sald sleeve and plunger, and means for admitting lubricant from said cylinder to said tube.

3. A grease gun comprising a cylinder, an outlet tube in one end thereof, a ported abutment in said tube, a sleeve slidable in said tube, a spring between said abutment and sleeve, a plunger in said tube and adapted to move forwardly toward said sleeve, a strongerA spring between said sleeve and plunger, and means for admitting lubricant from said cylinder to Isaid tube, said plunger having a portion adapted to enter and obstruct said sleeve.

lll. A grease gun comprising a cylinder, an outlet tube in one end thereof, a ported abutment in said tube, a check valve in the port of said abutment and mounted to open outwardly of said cylinder, a sleeve slidable in said tube, a spring between said abutment and sleeve, a plunger in said tube and adapted to move forwardly towards said sleeve, a strongler spring between said sleeve and plunger, and means for admitting lubricant from said cylinder to said tube,said plunger having a portion adapted to enter and obstruct said sleeve.

y 5. A grease gun comprising a. cylinder, an outlet tube in one end thereof, a ported abutment in said tube, a sleeve, slidable in said tube, a spring between said abutment and sleeve, a plunger slidably mounted in said tube and dimensioned for a sliding t in said sleeve whereby to drive lubricant through said sleeve, a stronger spring between said sleeve and plunger, said tube having ports in communication with said cylinder, whereby said tube is lled with lubricant on retraction of said sleeve from said abutment under action of said first named spring.

In testimony whereof I affix my signature.-

PETER GRESSER.

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